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Agricultural  Experiment  Station 


BULLETIN  No. 


RADIUM  AS  A  FERTILIZER 


BY  CTEIL  G.  HOPKINS  AND  WARD  H.  SACHS 


URBANA,  ILLINOIS,  JANUARY,  1915 


SUMMARY  OP  BULLETIN  No.  177 

1.  The  properties  of  radium  place  it  in  the  front  rank  among  the  remark- 
able discoveries  of  modern  times.  Page  389 

2.  Earlier  investigations  have  shown  that  radium  may  affect  the  physio- 
logical processes  of  plants.  Page  390 

3.  Some  conclusions  have  been  drawn  from  rather  discordant  data,  to  the 
effect  that  radium  is  a  wonderful  crop  stimulant  and  that  the   application  of 
radio-active  material  to  the  soil  is  a  profitable  procedure  for  the  gardener  or 
farmer.  Page  391 

4.  A  careful  study  of  the  data  reported  shows  that  the  conclusions  drawn 
and  the  claims  made  were  not  justified  by  the  facts  presented.  Page  394 

5.  The  trustworthy  results  from  two  years  of  field  trials  by  the  Illinois 
Experiment  Station  show  that  radium  applied  at  a  cost  of  $1,  $10,  or  $100  per 
acre  produced  no  effect  upon  the  crop  yields  either  the  first  or  the  second  season. 

Page  395 

6.  Upon  careful  analysis  of  the  known  facts,  radium,  notwithstanding  its 
wonderful  energy,  is  found  to  afford  no  foundation  for  reasonable  expectation 
of  increased  crop  yields.  Page  400 

7.  Both  consumers  and  producers  should  stand  for  positive  soil  improvement 
and  for  permanent  soil  preservation,  and  opposed  to  soil  depletion,  land  ruin,  and 
ultimate  farm  abandonment.  Page  400 


RADIUM  AS  A  FERTILIZER 

BY  CYEIL  G.  HOPKINS,  CHIEF  IN  AGRONOMY  AND  CHEMISTRY,  AND 
WAED  H.  SACHS,  ASSOCIATE  IN  CHEMISTRY 

With  the  discovery  of  radio-activity  by  Becquerel  in  1896,  and 
of  radium  itself  by  M.  and  Mme.  Curie  in  1898,  science  revealed  a 
property  of  matter  and  a  source  of  energy  hitherto  unknown;  and 
the  facts  already  established,  the  predictions  or  claims  made,  and  the 
general  interest  in  the  subject  seemed  to  justify  an  investigation  under 
field  conditions  of  the  possible  value  of  radium  as  a  fertilizer,  or  of 
radio-activity  as  a  crop  stimulant. 

THE  CHEMICAL  ELEMENTS 

All  matter  is  composed  of  chemical  elements,  which  are  considered 
permanent  or  indestructible,  altho  they  may  change  their  form  physi- 
cally and  may  enter  into  various  compounds  chemically.  Thus  car- 
bon (C)  occurs  in  the  free  state  in  the  diamond,  in  graphite,  and  in 
coal.  It  also  occurs  in  solid  compounds,  such  as  limestone  (CaC03) 
and  sugar  (C^H^O^);  in  liquid  form,  as  carbon  disulfid  (CS2), 
benzene  (C6H6),  chloroform  (CHC13),  etc.;  and  in  many  gases,  such 
as  carbon  dioxid  (C02),  marsh  gas  (CH4),  acetylene  (C2H2). 

About  eighty  chemical  elements  have  been  found,  but  most  of  them 
are  very  rare  and  only  ten  are  known  to  be  essential  for  crop  produc- 
tion. They  are:  carbon  and  oxygen,  secured  thru  the  leaves  from 
the  carbon  dioxid  of  the  air;  hydrogen,  from  water  absorbed  by  the 
roots;  and  seven  elements  secured  from  the  soil — nitrogen,  phos- 
phorus, potassium,  calcium,  magnesium,  iron,  and  sulfur.  Legume 
crops  may  also  secure  nitrogen  from  the  air  by  means  of  root-tubercle 
bacteria. 

THE  PROPERTIES  OF  RADIUM 

Radium  possesses  most  of  the  properties  of  a  true  chemical  ele- 
ment, but  it  also  possesses  in  most  remarkable  degree  the  peculiar 
and  newly  discovered  property  of  spontaneous  and  continuous  ema- 
nation of  particles,  and  radiation  of  energy,  called  radio-activity. 
Radium  is  a  solid  substance,  but  it  disintegrates  or  gives  off  particles 
of  matter  which  further  disintegrate,  yielding  as  one  final  product 
the  chemical  element  helium1  (an  inert  gas).  The  speed  with  which 

JAt  least  98  percent  of  the  total  energy  evolved  by  radium  is  due  to  the  libera- 
tion of  helium  atoms,  altho  helium  appears  to  constitute  only  about  10  percent 
of  radium.  (The  remaining  90  percent  is  thought  by  some  to  be  lead.) 

389 


390  BULLETIN  No.  177  [January, 

the  emanated  helium  particles  are  projected  from  radium  is  about 
12,000  miles  per  second,  compared  with  186,000  miles  per  second  as 
the  velocity  of  ordinary  light.  The  mass  of  radium  is  not  permanent, 
but  is  reduced  to  one-half  in  about  1760  years,  to  one-fourth  in  3520 
years,  to  one-eighth  in  5280  years,  and  so  on. 

Radium  continuously  emits  or  radiates  heat,  light,  and  electricity. 
The  amount  of  heat  evolved  is  relatively  enormous.  A  given  quantity 
of  radium  emits  sufficient  heat  to  raise  an  equal  weight  of  water  from 
the  freezing  point  to  the  boiling  point  in  less  than  one  hour,  and  this 
radiation  of  heat  continues  hour  after  hour,  with  gradual  reduction 
to  one-half  the  quantity  in  about  1760  years. 

Thus  the  total  quantity  of  heat  ultimately  evolved  by  a  pound  of 
radium  would  be  sufficient  to  raise  more  than  fifteen  million  pounds 
of  water  from  freezing  to  boiling  temperature,  whereas  a  pound  of 
good  Illinois  coal  has  power  to  change  only  seventy-five  pounds  of 
water  from  freezing  to  boiling.  In  other  words,  one  pound  of  radium 
would  ultimately  furnish  more  heat  than  one  hundred  tons  of  coal; 
and  in  total  ultimate  energy1  (including  heat,  light,  electricity,  etc.) 
one  pound  of  radium  would  be  equivalent  to  more  than  one  hundred 
fifty  tons  of  coal,  or  to  more  than  seventy  thousand  horse-power  days 
of  twenty-four  hours  each.  On  the  other  hand,  the  total  energy  of  a 
quantity  of  coal  can  be  secured  almost  instantly,  whereas  the  rate  of 
disintegration  of  radium  is  fixed,  so  that  only  half  its  total  energy 
becomes  liberated  in  about  1760  years;  but,  expressed  in  terms  of 
continuous  work,  about  nine  pounds  of  radium  would  be  equivalent  to 
one  horse-power.2 

SOME  EARLIER  EXPERIMENTS 

Many  experiments  have  been  made  to  ascertain  the  effect  of  radio- 
activity on  plant  growth;  and  in  general  it  has  been  found  that  a 
distinct  influence  is  exerted  if  sufficient  radium  is  used,  altho  some 
experimenters  report  negative  results. 

In  summarizing  his  investigations  in  the  Popular  Science  Monthly, 
Volume  74,  pages  222-232,  Gager  states  that  radium  acts  under  certain 
conditions  as  a  stimulus  to  physiological  processes  of  plants,  but  that 
it  may  retard  or  inhibit  development,  or  even  kill  the  plant,  if  used 
in  too  great  strength  or  for  too  long  a  period.  Acqua,  an  Italian  in- 
vestigator, reports  retarded  root  development,  but  little  or  no  direct 

investigations  show  that  one  gram  of  radium  emits  enough  heat  to  raise  118 
grams  of  water  one  degree  centigrade  in  one  hour,  or  118  calories,  and  indicate 
enough  total  energy  to  decompose  one  gram  of  water  into  hydrogen  and  oxygen 
every  twenty-four  hours,  equivalent  to  3822  calories,  or  nearly  160  calories  per 
hour. 

2Roscoe  and  Schorlemmer,  Treatise  on  Chemistry  (1913),  Volume  II,  page 
1423,  state  that  "it  appears  that  one  pound  of  radium  emits  energy  at  the  rate 
of  10,000  horse-power";  but  they  have  evidently  compared  radium  energy  per 
day  with  horse-power  per  second,  and,  since  there  are  86,400  seconds  in  a  day, 
the  corrected  comparison  shows  about  one  horse-power  for  8.64  pounds  of  radium. 


1915]  RADIUM  AS  A  FERTILIZER  391 

effect  upon  stems  or  leaves.  Fabre,  a  French  scientist,  found  some 
beneficial  effects  from  radio-activity  corresponding  to  emanations  of 
one  and  one-half  microcuries1  for  each  two  liters*  of  air,  but  injury 
from  greater  strength. 

Efforts  are  already  being  made  to  add  radio-active  substances  to 
the  list  of  commercial  fertilizers  and  stimulants  that  farmers  are 
urged  to  buy,  and  this  preliminary  report  is  issued  in  order  that  the 
information  thus  far  secured  may  be  available  to  those  who  are  in- 
terested and  who  might  otherwise  be  led  to  waste  money  that  should 
be  invested  in  rational  soil  enrichment. 

RUSBY'S  EXPERIMENTS 

In  the  New  York  Times  of  October  25,  1914,  a  full  page  is  devoted 
to  radium  as  "A  Wonderful  Stimulant  of  Farmers'  Crops."  This 
article,  with  its  illustrations  and  data,  is  credited  to  H.  H.  Rusby, 
M.  D.,  of  the  Columbia  University  College  of  Pharmacy.  The  fol- 
lowing statements  are  direct  quotations : 

"In  October,  1913,  I  arranged  with  the  Standard  Chemical  Company  of 
Pittsburgh,  Penn.,  to  make  preliminary  trials  on  an  extensive  scale.  In  view  of 
the  cost  of  radium  and  its  preparations,  the  reader  may  wonder  how  such  an  ex- 
periment could  be  undertaken.  It  requires  about  400  tons  of  radium  ore  of  stand- 
ard quality  to  yield  a  gram,  about  fifteen  and  a  half  grains,  of  radium,  which 
amount  could  easily  be  carried  on  a  man's  thumb  nail.  The  regular  market  price 
is  $10,000  a  grain,  or  $120,000  a  gram,  equal  to  $70,000,000  a  pound.  This  prob- 
lem was  solved  by  making  use  of  the  finely  powdered  residue  remaining  after  all 
the  radium  possible  has  been  extracted,  but  leaving  some  two  or  three  milligrams 
to  the  ton,  worth  some  $300,  yet  a  by-product  unless  a  special  use  for  it  could  be 
discovered. ' ' 

"That  the  application  of  such  material  to  the  soil  is  a  profitable  procedure 
for  the  gardener  or  farmer  may  be  understood  when  it  is  seen  that  such  increases 
in  production  resulted  as  29  per  cent,  in  lettuce,  17  per  cent,  in  lima  beans,  35 
per  cent,  in  cucumbers,  35  per  cent,  to  44  per  cent,  in  different  varieties  of  squash, 
80  per  cent,  in  Rocky  Ford  muskmelon,  24  per  cent,  in  carrots,  50  per  cent,  in 
sweet  corn,  and  70  per  cent,  in  radishes,  and  that  nearly  all  vegetables  are  won- 
derfully improved  in  their  table  qualities." 

"My  experiments  and  observations  included  the  winter  culture  of  radishes 
in  a  market  gardener's  greenhouse,  some  seedlings  in  window  boxes  in  my  own 
home;  field  crops  covering  more  than  one  hundred  acres  at  Northfield,  Ohio,  under 
the  direction  of  W.  W.  Darling;  an  experimental  garden  at  Pittsburgh,  and  the 
plantation  of  an  acre  and  a  half  at  Nutley,  N.  J.,  of  which  I  have  had  imme- 
diate personal  charge  throughout  the  season." 

JA  microcurie  is  a  millionth  part  of  a  curie,  the  unit  of  measurement  for 
radio-activity,  which  is  the  quantity  of  radium  emanation  in  equilibrium  with  one 
gram  of  radium.  In  other  words,  the  curie  (named  from  the  discoverers)  repre- 
sents the  constant  or  continuous  energy  of  one  gram  of  radium. 

2A  liter  holds  1,000  cubic  centimeters,  or  1,000  grams  of  water;  it  is  about 
one  quart,  and  corresponds  to  about  a  4-inch  cube,  or  64  cubic  inches.  On  the 
basis  of  one  and  one-half  microcuries  for  each  space  four  inches  square  and  eight 
inches  high,  this  application  corresponds  to  588,060  microcuries,  or  588  milligrams 
of  radium,  per  acre  of  land. 


392 


BULLETIN  No.  177 


[January, 


POUNDS  OP  PKODUCE  EEPORTED  FROM  EADIUM  EXPERIMENTS  AT  NUTLET,  N.  J. 


Applied  per  Acre 


Ore  Ta 
Badiun 

ilings  (B.  A.  F.),  Ibs  

200 
.25 

100 
.12 

50 
.06 

25 
.03 

0 
0 

i,  milligrams   

Plot  Nos  

AA 

BB 

CC 

DD 

X 

j. 
2 
2 
3 
3 
4 
4 
5 
5 
6 
7 
8 
9 
10 
11 

12 
13 

14 
15 
16 
17 
18 
18 
19 

20 
21 
22 
23 
24 
25 
26 
27 
28 
29 
30 
31 
32 
33 
34 

Early  Celery  (No  data) 
Telephone  peas   

21 
13 
32 
4 

133 
85 
160 
169 
181 
8 
4 

21 
16 
31 
9 

132 
104 
160 
226 
270 
8 
6 

23 
15 
26 
11 

133 
138 
118 
242 
309 

9 
4 

19 
21 
35 
16 

126 
118 
120 
213 
293 
10 
3 

22 
16 
27 
16 

133 
111 
153 
267 
330 
7 
5 

Second  crop,  Cow  Horn  Turnips  (No  data) 
Nott  's  peas   

Second  crop,  Globe  Turnips  (No  data) 
Lettuce    

Second  crop,  Savoy  Cabbage  (No  data) 

Second  crop,  Late  Celery  (No  data) 
Beets             .       .       

Carrots    

Esrer  Plant  . 

Late  Tomatoes  

Early  Tomatoes  

Cucumbers    .                  

Cucumbers  small         

Cucumbers   total           

12 
33 
14 

54 

14 

35 

28 

57 
81 

56 
243 
412 
92 
404 
232 

16 
80 
233 

92 
103 

83 
340 

13 

33 

24 

64 

78 

65 
321 
388 
82 
458 
150 

13 
90 
226 

90 
116 
72 

378 

13 

30 
29 

66 
71 

66 
222 
280 
93 
420 
100 

13 
95 
258 

95 
68 
50 
333 

12 
31 
29 

65 
58 

61 
206 
349 
80 
405 
162 

13 
63 
188 

88 
73 
46 
269 

String  Beans   

Early  Peppers  

Onions  (No  data) 
Parsnips  (No  data) 
Navy  Beans  (No  data) 
Red  Kidney  Beans  (No  data) 
Turnip  Radish  

Second  crop,  Late  Celery  (No  data) 
Long  Radish    

Second  crop,  Late  Celery  (No  data) 
Early  Eose  Potatoes  

48 
277 
384 
68 
460 
185 

19 
81 
.  217 

95 
87 
39 
370 

Pumpkins    

Early  Cabbage  

Dwarf  Lima  Beans   

Late  Cabbage    

Hubbard  Squash   

Crimson  Clover  (No  data) 
Late  Peppers  

Late  Corn    

Delicious  Squash  

Queen  Potatoes  (No  data) 
Early  Corn  

Hackensack    Muskmelons    

Eocky  Ford  Muskmelons  

Watermelons    . 

1915}  RADIUM  AS  A  FERTILIZER  393 

"In  Mr.  Flannery's  garden  I  particularly  noted  the  great  gain  of  turnips 
and  beets  under  the  radium  influence  over  those  without  it." 

"The  growing  crops,  which  I  have  observed  with  great  care  on  various  occa- 
sions, have  shown  results  in  all  respects  similar  to  those  recorded  at  my  Nutley 
plantation,  which  I  shall  now  describe." 

"One  plot,  AA,  was  treated  with  radio-active  fertilizer  at  the  rate  of  200 
pounds  to  the  acre;  another,  BB,  with  100  pounds;  a  third,  CO,  with  50  pounds; 
DD,  with  25  pounds,  and  X,  with  none.  Each  set  of  plots  was  nineteen  feet  wide, 
and  the  plots  composing  the  sets  were,  respectively,  five,  thirteen,  nine,  or  twenty 
feet  by  nineteen  feet,  according  to  the  nature  of  the  crop.  Each  plot  was  separated 
from  those  on  its  four  sides  by  paths  three  feet  wide,  except  for  the  central  road, 
which  was  six  feet  wide." 

"In  the  accompanying  table  each  plot  is  indicated  by  the  number  of  pounds 
of  E.  A.  F.  (radio-active  fertilizer)  that  it  received  to  the  acre." 

'"'  In~conclusion,  it  may  be  stated  that  the  yield  of  most  crops  can  be  in- 
creased by  the  addition  of  some  amount  of  radio-active  fertilizer,  the  amount 
differing  with  different  crops.  The  beneficial  effects  continue  over  successive 
crops,  probably  for  many  years.  The  largest  amount  required  by  any  crop  would 
cost  less  than  the  increased  market  value  of  such  crop  of  the  first  year. ' ' 

"The  fertility  of  unused  ground  will  spontaneously  increase  at  a  much  greater 
rate  when  treated  by  radium." 

It  is  to  be  noted  that  Rusby  credits  the  ore  tailings  with  the  same 
radium  content  (about  2y2  milligrams  per  ton)  as  the  original  ore 
(1000  milligrams  in  400  tons)  ;  but  it  is  easily  possible  that  the  by- 
product for  which  the  Standard  Chemical  Company  desires  to  find 
a  market  is  as  rich  in  radium  as  the  ore  itself ;  and  the  fact  that  Mr. 
J.  M.  Flannery  is  president  of  the  Standard  Chemical  Company  lends 
special  interest  to  the  results  observed  "in  Mr.  Flannery's  garden," 
showing  ' '  the  great  gain  of  turnips  and  beets  under  the  radium  influ- 
ence," altho  the  beets  on  Plot  6  at  Nutley  (see  table)  show  slightly 
decreased  yields  in  two  cases  and  no  benefit  in  the  other  two.  The 
complete  data  are  not  reported  for  turnips  at  Nutley,  but  Rusby 
states  that  the  radium  influence  from  the  25-pound  application  of  ore 
tailings  even  crossed  the  3-foot  path  and  made  the  turnips  on  that 
(south)  end  of  the  untreated  plot  "twice  as  large  and  strong  as  those 
at  the  northern  ends. ' '  He  adds  the  following : 

"There  is  an  exactly  similar  difference  among  the  turnips  in  the  25-pound 
plot,  those  at  the  southern  ends  of  the  rows,  separated  by  3  feet  from  the  50-pound 
plot,  being  twice  as  large  as  those  at  the  northern  ends,  with  the  same  regular 
gradation.  Between  the  50-pound  and  the  100-pound  plots  there  is  little  differ- 
ence, showing  that  50  pounds  (.06  milligram  of  radium  per  acre)  produces  about 
the  maximum  effect  on  turnips. 

"Between  the  100  and  the  200-pound  plots,  however,  there  is  a  similar  but  re- 
verse relation.  The  turnips  in  the  200-pound  plot  are  stunted  by  an  excess  of 
radium,  just  as  was  the  spinach  that  occupied  the  same  plot1  in  the  early  spring. ' ' 

*The  published  diagram  of  the  experimental  plots  at  Nutley,  N.  J.,  shows 
that  the  spinach  was  followed  not  by  turnips  but  by  late  celery,  and  that  turnips 
were  grown  only  after  peas.  In  the  accompanying  tabular  statement  will  be 
found  all  of  the  data  reported  (expressed  in  even  pounds  per  plot),  and  also  in- 
formation concerning  the  order  of  planting  on  the  various  plots,  as  shown  in  the 
diagram;  but  the  data  for  potatoes  may  have  been  secured  from  Plot  30  instead 
of  Plot  20;  otherwise  the  original  publication  is  clear. 


394  BULLETIN  No.  177  [January, 

No  information  is  given  as  to  the  amount  of  radium  applied  for 
turnips  on  Mr.  Flannery's  garden,  but  it  is  of  interest  to  note  that 
Fabre  reports  beneficial  results  on  plant  growth  from  radium  up  to 
588  milligrams  per  acre,  or  more  than  2000  times  the  amount  Rusby 
found  to  be  injurious  for  turnips. 

A  careful  study  of  Kusby  's  data  suggests  that  all  of  the  differences 
which  he  records  may  have  been  caused  by  natural  variations  in  the 
soil  or  other  influences,  rather  than  by  the  radium.  Thus  his  report 
of  29  percent  increase  in  lettuce  is  based  on  Plot  DD,  but  the  ad- 
joining plot,  CO,  shows  4  percent  decrease.  The  17  percent  increase 
reported  for  lima  beans  is  based  upon  Plots  BB  or  DD,  but  the  inter- 
mediate plot,  CC,  shows  only  3  percent  increase,  while  AA  shows  15 
percent  decrease. 

The  35  percent  increase  reported  for  cucumbers  is  based  only 
upon  the  larger  size  from  Plot  DD,  but  the  small  cucumbers  show  40 
percent  decrease  on  the  same  plot,  and  the  total  crop  shows  little  ef- 
fect— none  with  the  heaviest  application.  To  find  35  and  44  percent 
increases  for  squash,  one  must  figure  results  from  25  pounds  of  ore 
tailings  with  Delicious  squash,  and  from  100  pounds  of  ore  tailings 
with  Hubbard  squash;  whereas  the  check  plot,  X,  produced  62  per- 
cent more  Hubbard  squash  than  where  25  pounds  of  ore  tailings  were 
applied.  In  other  words,  the  minimum  application  seems  to  have 
increased  markedly  the  yield  of  Delicious  squash,  but  appears  to  have 
stunted  in  a  marked  degree  the  growth  of  Hubbard  squash. 

The  increases  claimed  with  muskmelons,  carrots,  sweet  corn,  and 
radishes  are  also  found  only  by  selecting  the  highest  results  from 
rather  discordant  data.  "With  nearly  all  of  the  crops  reported  upon, 
radium  appears  to  have  decreased  the  yields  in  some  of  the  trials, 
but  neither  increase  nor  decrease  correlates  in  any  general  way  with 
the  amount  of  radium  applied.  The  smallest  yield  of  Hackensack 
muskmelon  was  with  the  smallest  application,  while  the  smallest  yield 
of  Rocky  Ford  muskmelon  was  with  the  largest  amount  of  radium. 
These  extremes  gave  equal  yields  of  early  corn  but  very  different  re- 
sults with  late  corn.  The  four  trials  with  carrots  show  two  increases 
and  two  decreases,  with  an  average  of  111  pounds,  exactly  the  same 
as  with  no  radium.  One  variety  of  radish  appears  benefited,  the 
other  stunted,  by  equal  amounts  of  radium.  Likewise,  25  pounds  of 
the  ore  tailings  helped  one  kind  of  peas  and  hindered  the  other,  while 
50  pounds  produced  similar  effects  but  in  the  reverse  order ;  and  200 
pounds  gave  50  percent  increase  with  late  peppers  and  50  percent 
decrease  with  early  peppers. 

Among  the  fifty-nine  trials  for  which  data  are  reported  on  one 
half  of  the  field  (Plots  1  to  20),  thirty-eight  show  no  benefit  from  ra- 
dium; while  on  the  other  side  of  the  "central  road"  thirty-nine  of 
the  forty-eight  trials  show  benefit.  In  other  words,  the  influence  of 
radium  was  usually  beneficial  on  one  side  of  the  road  and  usually  in- 


1915}  RADIUM  AS  A  FERTILIZER.  395 

jurious  on  the  other  side,  which  certainly  strongly  suggests  that  the 
variations  in  yield  of  crops  were  due  to  some  other  differences  than 
radium  applications. 

Busby's  statement  that  "the  fertility  of  unused  ground  will  spon- 
taneously increase  at  a  much  greater  rate  when  treated  by  radium" 
appears  to  be  an  opinion,  not  an  established  fact. 

ILLINOIS  EXPERIMENTS 

In  the  spring  of  1913,  thru  the  kindness  of  the  Standard  Chemi- 
cal Company  of  Pittsburgh,  the  University  of  Illinois  Agricultural 
Experiment  Station  was  enabled  to  begin  a  series  of  field  experiments 
with  radium  as  a  fertilizer  or  crop  stimulant.  This  company  re- 
ported 1500  tons  of  uranium-radium  ore  (carnotite)  as  the  annual 
product  from  its  Colorado  mines,  and  was  said  to  be  the  only  concern 
manufacturing  radium  salts  in  America.  The  company  was  deeply 
interested  in  having  the  experiments  conducted,  and  the  radium  salts 
furnished  to  us  were  prepared  under  the  direction  of  Dr.  Otto  Brill 
and  Dr.  Charles  H.  Viol  of  the  radium  research  laboratory  of  the 
Standard  Chemical  Company,  the  quality  and  strength  of  the  prepara- 
tions being  thus  assured. 

Since  the  "radium  plots"  were  made  to  run  crosswise  over  other 
regular  experiment  plots,  these  investigations  were  conducted  with- 
out interfering  with  our  other  experiments,  and  at  small  extra  ex- 
pense,— chiefly  for  taking  weights  of  produce  "in  both  directions," 
the  expense  of  applying  the  radium  having  been  borne  by  the  Stand- 
ard Chemical  Company. 

The  value  of  radium  is  about  $100  per  milligram;  and  it  may 
well  be  noted  that  it  takes  453,600  milligrams  (453.6  grams)  to  make 
one  pound.  The  total  amount  of  radium  thus  far  secured  in  all  the 
laboratories  and  factories  of  the  world  is  estimated  at  eight  grams,  or 
less  than  one-third  of  an  ounce. 

In  order  that  the  field  investigation  might  have  direct  relation  to 
practical  Illinois  agriculture,  the  radium  was  used  at  three  rates  of 
application,  costing,  respectively,  $1,  $10,  and  $100  per  acre;  or  in 
amounts  of  .01  milligram,  .1  milligram,  and  1  milligram  of  radium 
per  acre.  If  the  effect  of  the  applications  should  be  marked  and  per- 
manent, even  the  initial  expense  of  $100  per  acre  might  be  desirable. 

The  fields  selected  for  these  experiments  were  the  north  division 
of  the  Series  200  and  the  south  division  of  the  Series  600  of  the 
Agronomy  plots  on  the  South  Farm  of  the  University  of  Illinois. 
Each  of  these  fields  contains  eighteen  fifth-acre  plots,  two  rods  wide 
and  sixteen  rods  long,  besides  some  division  and  border  strips, 
making  each  field  sixteen  rods  wide  east  and  west,  and  thirty-eight 
rods  long  north  and  south.  For  the  radium  experiments  each  field 
was  divided  transversely  into  eight  plots  two  rods  wide  and  thirty- 


396 


BULLETIN  No.  177 


[January, 


eight  rods  long,  numbered  one  to  eight,  from  west  to  east.  No  radium 
was  applied  on  Plots  1  and  5 ;  where  applied,  the  rates  per  acre  were 
.01  milligram  on  Plots  2  and  6,  .1  milligram  on  3  and  7,  and  1  milli- 
gram on  4  and  8. 

On  Series  200  and  on  the  west  part  of  Series  600,  the  radium  was 
applied  in  a  solution  of  radium  barium  chlorids  diluted  with  distilled 
water,  the  check  plots  receiving  the  same  quantity  of  distilled  water 
without  radium.  On  the  east  part  of  Series  600,  solid  radium  barium 
sulfates  were  applied  after  being  diluted  by  thoro  mixing  and  pul- 
verizing with  dry  soil  from  the  field,  the  check  plot  receiving  the 
same  weight  of  soil  without  radium.  The  pulverized  soil  was  applied 
with  a  force-feed  grain  drill,  and  the  solutions  with  an  Aspinwall  bar- 
rel sprayer.  For  the  heaviest  applications,  only  528  cubic  centi- 
meters of  the  solution  of  chlorids  and  770  grams  of  the  sulfates  were 
required  per  acre,  amounts  which  are  too  small  to  produce  appre- 
ciable indirect  effects,  such  as  might  possibly  be  caused  by  100  pounds 
or  more  of  crude  salts  per  acre. 

On  both  fields  corn  was  grown  in  1913  and  soybeans  in  1914.  In 
the  accompanying  tables  are  reported  the  yields  per  acre  in  bushels, 
except  where  soybean  hay  was  harvested,  which  is  reportd  in  pounds 
per  acre.  Owing  to  other  experimental  work  involving  some  varia- 
tions in  planting,  only  part  of  Series  600  furnished  comparable  data 
in  1913,  only  twenty-four  separate  trials  being  provided,  as  shown  in 
Table  3.  . 

Aside  from  the  corn  grown  on  Series  200  in  1913,  the  average  re- 
sults reported  in  the  tables  are  considered  trustworthy  within  the 
limits  of  variation  shown. 

TABLE  1. — CORN  ON  SERIES  200,  1913 
(Bushels  per  acre) 


Radium  per 

acre,  mgs.  .  . 

0 

.01 

.1 

1 

0 

.01 

.1 

1 

Plot  Nos.   ... 

1 

2 

3 

4 

5 

6 

7 

8 

241-2 

29.6 

33.6 

40.0 

38.9 

36.1 

35.5 

33.7 

35.6 

243 

38.2 

36.0 

41.9 

45.4 

39.6 

39.3 

38.6 

40.6 

244-5 

34.5 

43.6 

38.9 

41.8 

31.1 

40.8 

48.7 

41.1 

246 

43.8 

38.0 

43.0 

45.8 

42.6 

48.8 

48.1 

50.2 

247-8 

40.1 

39.0 

41.1 

39.9 

36.5 

43.0 

41.4 

43.4 

249 

48.5 

40.7 

52.5 

54.9 

52.1 

46.3 

46.4 

46.3 

250 

49.1 

45.2 

49.9 

52.5 

51.4 

44.4 

35.9 

34.5 

251-2 

51.1 

46.6 

39.8 

37.1 

42.3 

42.2 

45.6 

46.6 

253 

44.1 

45.9 

53.1 

45.7 

45.4 

53.3 

62.6 

62.6 

254-5 

49.2 

49.6 

48.4 

55.3 

63.7 

67.7 

67.8 

66.6 

256 

43.5 

40.0 

46.2 

45.8 

54.1 

61.8 

57.3 

66.2 

257-8 

34.4 

36.0 

43.1 

50.6 

54.7 

54.2 

59.6 

58.0 

Average 

42.2 

41.2 

44.8 

46.1 

45.8 

48.1 

48.8 

49.3 

Average  gain 

2.6 

3.9 

2.3 

3.0 

3.5 

Average  loss 

1.0 

1915] 


RADIUM  AS  A  FERTILIZER 


397 


TABLE  2. — SOYBEANS  ON  SERIES  200,  1914 
(Bushels  per  acre) 


Radium  per 
acre,  mgs.  .  . 

0 

.01 

.1 

1 

0 

,01 

.1 

1 

Plot  Nos.    ... 

1 

2 

3 

4 

5 

6 

7 

8 

241-2 

18.8 

19.1 

20.8 

20.3 

19.5 

19.4 

19.8 

20.5 

243 

22.5 

20.9 

21.7 

22.3 

18.9 

19.3 

20.6 

21.5 

244-5 

26.0 

27.3 

22.4 

23.0 

22.7 

24.4 

25.6 

22.2 

246 

28.9 

25.5 

25.2 

23.5 

21.9 

26.3 

27.0 

24.8 

247-8 

28.9 

28.9 

29.4 

27.3 

23.7 

24.8 

24.2 

23.5 

249 

28.7 

28.5 

28.0 

30.2 

25.8 

26.7 

25.1 

23.3 

250 

28.4 

28.8 

28.7 

27.6 

25.8 

26.7 

23.1 

21.1 

251-2 

25.3 

29.7 

29.5 

26.6 

24.0 

26.6 

28.3 

27.0 

253 

27.0 

26.9 

27.9 

26.2 

25.8 

28.5 

29.3 

29.8 

254-5 

25.3 

24.5 

24.8 

24.9 

24.8 

28.0 

28.3 

26.9 

256 

26.2 

24.3 

28.1 

27.7 

26.1 

28.5 

29.4 

29.5 

257-8 

22.0 

17.6 

23.0 

26.0 

27.6 

24.8 

28.7 

29.1 

Average 

25.7 

25.2 

25.8 

25.4 

23.9 

25.3 

25.8 

24.9 

Average  gain  . 

.1 

1.4 

1.9 

1.1 

Average  loss  .  . 

.5 

.2 

TABLE  3. — CORN  ON  SERIES  600,  1913 
(Bushels  per  acre) 


Planted   

2  kernels  per  hill 

3  kernels  per  hill 

Radium  per 
acre,  mgs.  . 

0 

.01 

.1 

1 

0 

.01 

.1 

1 

Plot  Nos.    .. 

1 

.2 

3 

4 

5 

6 

7 

8 

Hills  33  by  36  inches 


N.  half,  A 

33.2 

33.2 

29.6 

27.0 

N.  half,  B 

37.3 

34.1 

28.3 

32.3 

S.   half,  A 

36.6 

38.7 

28.8 

25.8 

S.  half,  B 

33.1 

34.5 

24.1 

24.7 

Average  .... 

35.0 

35.1 

27.7 

27.4 

Hills  33  by  39.6  inches 


N.  half,  A 

31.6 

34.0 

28.3 

27.4 

N.  half,  B 

32.8 

36.5 

31.8 

34.2 

S.   half,  A 

34.1 

32.6 

26.1 

26.6 

S.   half,  B 

32.6 

31.4 

25.7 

18.7 

Average    .  .  . 

32.8 

33.6 

28.0 

26.8 

Hills  33  by  44  inches 


N.  half,  A 

33.3 

30.3 

28.2 

28.1 

N.  half,  B 

30.9 

28.9 

24.9 

27.2 

S.   half,  A 

33.5 

38.7 

27.6 

29.3 

S.   half,  B 

27.2 

33.6 

26.7 

20.4 

Average    .  .  . 

31.2 

32.9 

26.9 

26.3 

.1 

.8 

1.7 

Average  loss  .  . 

.3 

1.2 

.6 

398 


BULLETIN  No.  177 


[January, 


TABLE  4. — SOYBEANS  ON  SERIES  600,  1914 
(Bushels  per  acre) 


Radium  per 

acre,  mgs.  .  . 

0 

.01 

.1 

1 

0 

.01 

.1 

1 

Plot  Nos.   .. 

1 

2 

3 

4 

5 

6 

7 

8 

661 

20.3 

15.4 

15.9 

17.3 

14.8 

17.7 

15.6 

16.5 

662 

18.2 

17.5 

15.2 

17.1 

16.6 

16.0 

15.6 

13.9 

663 

20  ;5 

20.6 

19.7 

19.7 

17.7 

17.9 

18.1 

21.6 

664 

16.4 

16.3 

16.5 

16.1 

15.0 

15.4 

15.5 

17.9 

665 

20.5 

19.7 

19.1 

16.5 

16.6 

15.5 

17.2 

19.3 

666 

17.7 

23.1 

18.5 

20.3 

17.4 

19.3 

17.3 

19.1 

667 

21.5 

20.7 

22.3 

18.2 

17.7 

19.2 

18.5 

21.7 

668 

28.4 

29.5 

28.1 

26.8 

23.6 

24.6 

23.7 

24.6 

669 

20.4 

18.9 

18.7 

18.0 

17.4 

19.9 

19.7 

21.5 

Average    .  .  . 

20.4 

20.2 

19.3 

18.9 

17.4 

18.3 

17.9 

19.6 

Average  gain 

1.0 

.5 

2  2 

Averaere  loss 

.2 

1.1 

1.5 

TABLE  5. — SOYBEAN  HAY  ON  SERIES  600,  1914 
(Pounds  per  acre) 


Radium  per 
acre,  mgs.  . 

0 

.01 

.1 

1 

0 

.01 

.1 

1 

Plot  Nos.  .. 

1 

2 

3 

4 

5 

6 

7 

8 

670 
671 
672 
673 
674 
675 
676 
677 
678 

3833 
4839 
3578 
3480 
3470 
3372 
3289 
3132 
3833 

4079 
5099 
3802 
4039 
3925 
3354 
3914 
3110 
4000 

3036 
4693 
2849 
3372 
2883 
2984 
3332 
4016 
4416 

2922 
4841 
2789 
3458 
2629 
3024 
3247 
3300 
4685 

2874 
4245 
2410 
3045 
2337 
2682 
3082 
2944 
4054 

2862 
4382 
2302 
2902 
2184 
2753 
2891 
2912 
4368 

2754 
4160 
2192 
2912 
1915 
2888 
3054 
2889 
4241 

2883 
4041 
2335 
2992 
2335 
2796 
3225 
3090 
4359 

Average  .  .  . 

3647 

3925 

3509 

3433 

3075 

3062 

3000 

3117 

Average  gain  . 

275 

42 

Average  loss  .  . 

138 

215 

13 

74 

VARIATIONS  DUE  To  DROUTH 

Series  600  possesses  an  unusually  satisfactory  degree  of  uniform- 
ity; but  on  Series  200  there  are  some  topographic  variations  which 
influence  the  rapidity  of  the  "run-off"  or  absorption  of  rain;  and  in 
very  dry  seasons,  with  occasional  dashing  showers,  when  moisture  is  a 
factor  of  great  importance,  these  variations  appear  in  the  crop  yields. 
From  April  11  to  September  11,  a  period  of  five  months,  the  total 
rainfall  in  1913  was  only  5.87  inches.  Under  these  adverse  conditions, 
even  the  average  results  from  Series  200  are  not  considered  trust- 
worthy, notwithstanding  the  large  number  of  separate  trials  making 
the  averages.  Considering  even  the  general  averages,  .01  milligram  of 
radium  appears  to  have  decreased  the  yield  of  corn  by  1  bushel  on  the 
west  part  of  the  field  and  to  have  made  2.3  bushels  increase  on  the  east 


1915]  RADIUM  AS  A  FERTILIZER  399 

part.  Again,  increasing  the  cost  of  radium  from  $1  to  $10  per  acre 
appears  to  have  increased  the  yield  by  3.6  bushels  on  the  west  part 
and  by  only  .7  bushel  on  the  east  part ;  and  the  further  increase  of  $90 
shows  apparent  gains  of  1.3  bushels  on  the  west  and  only  .5  bushel 
on  the  east  part  of  this  field.  Of  course  no  conclusions  should  be 
drawn  from  such  discordant  plus  and  minus  results. 

TRUSTWORTHY  DATA 

The  results  with  soybeans  on  Series  200  in  1914  agree  within  nar- 
row limits  in  showing  no  benefit  from  the  radium  applied  the  year 
before,  the  west  half  of  the  field  giving  slightly  smaller  and  the  east 
half  slightly  larger  average  yields  where  radium  was  added  than  on 
the  check  plots. 

On  Series  600  the  average  yields  of  corn  in  1913  were  slightly 
larger  with  two  kernels  per  hill  and  slightly  smaller  with  three  ker- 
nels per  hill  where  radium  was  applied,  but  the  apparent  gains  and 
losses  are  all  well  within  the  experimental  error  or  plot  variation,  and 
the  general  average  indicates  no  effect  from  the  radium.  The  yields 
of  soybean  seed  on  the  north  half  of  this  field  in  1914  likewise  reveal 
no  influence  from  radium,  all  rates  of  application  indicating,  on  the 
average,  slight  decreases  for  radium  on  the  west  side  and  slight  in- 
creases on  the  east  side  of  the  field  With  the  soybean  hay  the  six  gen- 
eral averages  show  no  effect  from  radium,  four  results  being  slightly 
below  the  checks  and  the  other  two  slightly  above. 

Thus  from  the  two  years'  work  we  have  six  trustworthy  average 
results  with  corn  (Table  2),  three  "for"  and  three  "against"  radium, 
and  we  have  eighteen  averages  with  soybeans  (Tables  3,  4,  and  5), 
nine  "for"  and  nine  "against"  radium.  In  all  of  these  trials  the 
average  variation  from  the  checks  is  so  slight  and  so  evenly  distrib- 
uted, "for"  and  "against,"  as  to  lead  only  to  the  conclusion  that  ra- 
dium applied  at  a  cost  of  $1,  $10,  or  $100  per  acre  produced  no  effect 
upon  the  crop  yields  either  the  first  or  second  season. 

EFFECT  OF  STIMULANTS 

Even  if  radium  or  other  radio-active  substances  were  to  increase 
crop  yields  when  applied  to  soils  in  sufficient  quantity,1  the  effect 
would  be  that  of  a  stimulant  and  the  increase  would  be  secured  at  the 
expense  of  the  soil.  Thus  the  soil  would  not  be  enriched  in  fertility, 
but  actually  impoverished  by  such  treatment.  This  result  follows 
also  for  all  forms  of  proposed  stimulation  for  soil  or  crop. 


1The  rate  of  application  mentioned  by  Fabre  (heretofore  referred  to) 
would  cost  about  $58,800  per  acre  at  present  prices  for  radium;  and  even  his 
beneficial  results  lack  general  verification  by  other  experiments. 


400  BULLETIN  No.  177  [January, 

Thus  the  use  of  electricity  has  been  advertised  by  commercial  in- 
terests, and  many  experiments  have  been  conducted  with  the  growing 
of  crops  under  a  network  of  electric  wires.  However,  a  careful  study 
of  the  results  reported  from  such  investigations  when  conducted  by 
public-service  institutions  reveals  no  important  effects  upon  plant 
growth,  altho  some  most  remarkable  results  have  been  reported  by 
investigators  employed  by  commercial  interests. 

Even  the  increased  yield  sometimes  secured  by  excessive  cultiva- 
tion is  at  the  expense  of  the  soil.  The  trustworthy  information  thus 
far  secured  in  Illinois  does  not  show  profitable  results  from  extra  deep 
tillage,  or  from  subsoiling,  either  with  subsoil  plows  or  with  dynamite ; 
but  even  if  such  practices  were  temporarily  profitable,  they  might  not 
be  advisable,  because  they  tend  to  make  soils  poorer,  and  the  same 
expense  in  limestone,  phosphate,  clover,  or  manure,  which  are  highly 
profitable  on  our  common  soils,  would  tend  toward  positive  soil  en- 
richment and  permanent  preservation  of  fertility. 

These  facts  and  principles  deserve  the  most  careful  consideration, 
for  they  are  of  permanent  interest  to  consumers  as  well  as  producers, 
and  to  industry  and  commerce  as  well  as  to  agriculture.  The  people 
of  the  state  and  of  the  United  States  should  stand  as  a  unit  for  soil 
building  and  soil  preservation,  and  opposed  to  soil  depletion,  land 
ruin,  and  ultimate  farm  abandonment. 

MISLEADING  CLAIMS 

As  a  rule,  the  claims  for  possible  stimulants  are  not  well  founded. 
Even  radium,  with  all  its  wonderful  energy,  is  found,  upon  careful 
analysis  of  the  known  facts,  to  afford  no  foundation  for  reasonable 
expectation  of  increased  crop  yields,  when  financial  possibilities  are 
considered.  It  is  true  that  the  total  ultimate  energy  developed  in 
1760  years  from  a  pound  of  radium  will  be  equivalent  to  seventy-five 
tons  of  coal,  or  to  35,000  horse-power  days  of  twenty-four  hours  each ; 
but  when  the  time  is  reduced  to  one  hundred  days  of  good  crop-grow- 
ing weather,  and  the  amount  of  radium  reduced  to  ten  milligrams, 
costing  $1,000  per  acre,  then  the  energy  emitted  from  the  radium  for 
the  possible  benefit  of  an  acre  of  corn  during  the  crop  season  would 
be  equivalent  to  one  horse-power  for  only  twenty-two  seconds;  and 
the  heat  evolved  by  $1,000  worth  of  radium  on  an  acre  of  land  in  one 
hundred  days  would  be  less  than  the  heat  received  from  the  sun  on 
one  square  foot  in  thirty  seconds. 

RATIONAL  SOIL  ENRICHMENT 

The  only  materials  which  need  be  added  to  the  most  common  Illi- 
nois lands  for  their  positive  and  permanent  enrichment  are  lime- 
stone, phosphorus,  and  organic  matter.  These  are  the  only  necessary 


1915}  RADIUM  AS  A  FERTILIZER  401 

materials  which  are  not  provided  naturally  in  inexhaustible  supply. 
Of  course  the  organic  matter  supplies  the  nitrogen,  whether  applied 
as  farm  manure  or  in  crop  residues  and  legume  crops  plowed  under. 
On  soils  subject  to  much  erosion,  the  application  of  phosphorus  is 
usually  not  profitable  or  necessary,  since  the  supply  is  renewed  from 
the  subsoil. 

On  peaty  swamp  soils  and  on  some  sand  lands,  potassium  is 
needed;  but  the  normal  lands  of  the  state  contain  in  the  plowed  soil 
of  an  acre  from  25,000  to  35,000  pounds  of  potassium  (from  30,000 
to  40,000  pounds  of  potash),  and  in  rational  systems  of  farming,  the 
addition  of  commercial  potassium  on  such  lands  is  unnecessary,  un- 
profitable, and  unwise. 

In  a  word,  the  well-informed  farmer  on  the  common  Illinois  land 
will  purchase  and  apply  limestone  and  phosphate;  but  he  will  grow 
the  organic  matter  on  the  farm,  secure  nitrogen  from  the  inexhausti- 
ble supply  in  the  air,  and  liberate  potassium  from  the  inexhaustible 
supply  in  the  soil;  and  he  will  not  waste  his  money  on  so-called 
"complete"  fertilizers,  nor  on  newly  advertised  soil  or  crop  stimu- 
lants. 

For  further  information  concerning  rational  soil  improvement, 
see  Circulars  110,  149,  and  165,  which  will  be  sent  free  of  charge  upon 
request;  and,  if  so  desired,  the  applicant's  name  and  address  will  be 
placed  upon  the  permanent  mailing  list  for  future  publications  by  the 
Agricultural  Experiment  Station,  Urbana,  Illinois. 


UNIVERSITY  OF  ILLINOIS-DRBANA 

Q  630.7IL6B  C001 

BULLETIN.  URBANA 
166-181  1914-15 


30112019528436 


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